20445305 has 12 divisors (see below), whose sum is σ = 26064300. Its totient is φ = 15393024.

The previous prime is 20445289. The next prime is 20445317. The reversal of 20445305 is 50354402.

It can be written as a sum of positive squares in 6 ways, for example, as 4541161 + 15904144 = 2131^2 + 3988^2 .

It is not a de Polignac number, because 20445305 - 2⁴ = 20445289 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5630 + ... + 8519.

It is an arithmetic number, because the mean of its divisors is an integer number (2172025).

Almost surely, 2^20445305 is an apocalyptic number.

It is an amenable number.

20445305 is a deficient number, since it is larger than the sum of its proper divisors (5618995).

20445305 is a wasteful number, since it uses less digits than its factorization.

20445305 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14188 (or 14171 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 23.

The square root of 20445305 is about 4521.6484825780. The cubic root of 20445305 is about 273.4415651423.

Adding to 20445305 its reverse (50354402), we get a palindrome (70799707).

The spelling of 20445305 in words is "twenty million, four hundred forty-five thousand, three hundred five".